Furthermore show how $\cos(2\theta) = \cos^2(\theta) - \sin^2(\theta)$ can be used to give the two variations of $\cos(2\theta) = 1 - 2\sin^2(\theta)$ and $\cos(2\theta) = 2\cos^2(\theta) - 1$
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Step 1: Start with the identity cos(2θ) = cos^2(θ) - sin^2(θ). Show more…
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